Hyaluronic Acid: What It Is and Why It's Great for Dry Skin

Let’s talk about the state of your skin. Is it itchy? thirsty? Does it feel a little tight? Considering it’s the dead of winter, we're going to venture a guess that the answer is likely yes. Really, show us a girl whose face isn't feeling dry right now, and we'll show you a girl who's been using hyaluronic acid (or someone with obnoxiously good genes, but let's ignore her for a minute).

While freezing-cold weather does skin no favors, and going from your warm office, apartment, or house into the cold (then back) isn’t helping, there is some good news: There are now more products than ever that work to replenish dry skin. And there’s one all-star ingredient in particular that gets the job done: hyaluronic acid. You’ve probably heard of it before, and if not, you’re about to see a lot more of it in the coming months because it’s the active ingredient in nearly every major skin care launch.

Here’s the scoop on the moisturizing powerhouse that all derms swear by—and the stuff you'll soon be telling everyone you know about.

So, first, what is hyaluronic acid?“Acid” may be the last thing you want to put on your parched face, but hyaluronic acid is not the burn-y kind (like alpha or beta hydroxy acids, which work to exfoliate your skin). H.A. occurs naturally in your body—in your joints, eyes, and—yes—skin. So what purpose does it serve in the last one? “It’s produced by fibroblasts, the same cells that make collagen, in the dermis, the second layer of skin,” says Neal Schultz, M.D., NYC dermatologist and founder of BeautyRx by Dr. Schultz. “It is the key molecule involved in skin moisture because it absorbs up to 1,000 times its weight in water.” Think of hyaluronic acid as a sponge in your skin that holds on to moisture and keeps your face looking plump and dewy.

Great! But what does hyaluronic acid actually do?“Hyaluronic acid does not occur naturally on the surface of your skin, but when applied [via skin care], it’s a wonderful moisturizing ingredient,” Dr. Schultz explains. When you apply an H.A. product, it works as a humectant. “Humectants basically pull water from the environment into your skin and are very hydrating,” says Joanna Vargas, celebrity facialist and founder of Joanna Vargas Skincare Collection. Basically, it serves as a big drink of water for your face, softening fine lines, making skin look firmer, and smoothing out even the roughest dry patches. It also “plumps and adds volume to your skin cells to make your skin more radiant and smooth,” Jessica Weiser,, MD., a dermatologist at New York Dermatology Group, adds. H.A. is also a popular ingredient for facial fillers. “We use hyaluronic acid fillers to replace volume, create lift, and make the contours of the face more youthful,” Dr. Weiser says.

And you use it…how?Humectants like hyaluronic acid typically have a watery texture and absorb quickly (think: liquidy serums), whereas emollients (i.e., creams and oils) are thicker and stay more on your skin’s surface, don’t absorb as quickly, and work to lock everything in. Hyaluronic acid is often combined with other runny humectants (like glycerin and urea) and water. The water part is important: “It gets bound by the hyaluronic acid and then delivered to your skin," Dr. Schultz explains. "This is one of the ways hyaluronic functions as the greatest moisturizing ingredient ever.”

But here’s the thing to remember with humectants: It’s important to combine or layer them with more emollient textures, as the thicker products will work to maintain the moisture the humectant provides. “They seal in moisture that is already there so it doesn’t evaporate,” Dr. Schultz explains. A good rule of thumb: You’ll want to top off an H.A. serum with an oil or a cream to make the results last. Most creams, on the other hand, already have both humectants and emollients (we like Beauty RX Soothing Moisture Cream), so they're OK to apply alone. (Or, if your skin is super oily, a serum may be enough.) As a skin care junkie, I always use both—serums because they’re more active, and then a cream as a veil of protection. Vargas also points out that regular exfoliation is key for getting the most out of your products; skin care absorbs so much better if you don’t have a bunch of dead skin cells sitting on the surface.

Got it! But last question: How do you figure out what's best for you?Good Q. Here are all the amazing new products that deliver H.A., and which will work best for your skin type or concern.

1. If you have extremely dry skin…Clarins Hydra-Essentiel Intensive Moisture Quenching Bi-Phase Serum has two different textures, and when you shake and apply the mixture to your face, it’ll revive even the most dehydrated skin. The active ingredient, along with H.A.: a succulent called the Leaf of Life, which is native to Madagascar and able to thrive amid harsh weather changes.

2. If you want to combat lines…Kate Somerville Wrinkle Warrior 2-in-1 Plumping Moisturizer and Serum is thick enough that you can probably get away with skipping your cream altogether. It packs three different sizes of hyaluronic acid—large, medium, and mini—to penetrate skin at various levels. It also has a few different amino acids that work to lessen lines and winkles. Bonus points: Whereas some hyaluronic products can leave skin a bit tacky, this gel leaves your face completely soft and matte, minimizing lines and doubling as a makeup primer.

3. If your skin is looking a little tired…Anytime Skinceuticals releases a serum, it’s a big freaking deal. The brand’s latest: the HA Intensifier. This serum not only contains 1.3 percent H.A. in various formats (fragmented, encapsulated, and at full molecular weight) to soften your skin, but also has purple rice extract (why it has a violet hue) and Pro-Xylane, to stimulate your skin’s cells that make collagen, boost H.A. levels, and prevent its natural breakdown. The takeaway: Most H.A. products work to hydrate the surface of your skin—this does that and helps build up the reservoir of H.A. in your dermis. Major.

4. If you prefer “clean” products…Drunk Elephant prides itself on using only clean, nontoxic ingredients with a combination of naturals and “safe synthetics” that deliver real results. The brand’s B-Hydra Intensive Hydration Gel doesn’t contain hyaluronic acid per se, but it does have sodium hyaluronate crossplymer, a relative of hyaluronic that the brand calls H.A.’s “adorable little sister.” According to Dr. Schultz, sodium hyaluronate is “functionally the same thing as our beloved hyaluronic acid,” so this will also work to rehydrate parched skin.

5. If you prefer a cream texture…There’s a reason Peter Thomas Roth Water Drench Hyaluronic Cloud Cream has its name. It feels dreamy when you apply it to your face at the end of a long day. It’s also extremely lightweight and transforms into a more watery texture as it warms up on your face.

6. If you have oily skin…Try L’Oréal Paris Hydra Genius Daily Liquid Care for Normal/Oily Skin. The beautiful thing about hyaluronic acid—and most humectants—is that they won’t clog pores. Because oily skin needs moisture too (and can get even greasier if you attempt to dry it out), L’Oréal’s aloe vera and H.A.-laced serum delivers moisture and a matte finish for those who battle shine.